HarmonyOS 底部弹窗问题

// xxx.ets  
@Entry  
@Component  
struct SheetTransitionExample {  
  @State isShow:boolean = false  
  @State isShow2:boolean = false  
  @State sheetHeight:number = 300;  
  @Builder myBuilder() {  
    Column() {  
      Button("change height")  
        .margin(10)  
        .fontSize(20)  
        .onClick(()=>{  
          this.sheetHeight = 500;  
        })  
      Button("Set Illegal height")  
        .margin(10)  
        .fontSize(20)  
        .onClick(()=>{  
          this.sheetHeight = -1;  
        })  
      Button("close modal 1")  
        .margin(10)  
        .fontSize(20)  
        .onClick(()=>{  
          this.isShow = false;  
        })  
    }  
    .width('100%')  
    .height('100%')  
  }  
  build() {  
    Column() {  
      Button("transition modal 1")  
        .onClick(() => {  
          this.isShow = true  
        })  
        .fontSize(20)  
        .margin(10)  
        .bindSheet($$this.isShow, this.myBuilder(), {  
          height: this.sheetHeight,  
          backgroundColor: Color.Green,  
          enableOutsideInteractive: true,  
          onAppear: () => {console.log("BindSheet onAppear.")},  
          onDisappear: () => {console.log("BindSheet onDisappear.")}  
        })  
    }  
    .justifyContent(FlexAlign.Center)  
    .width('100%')  
    .height('100%')  
  }  
}